1. Field of the Invention
The present invention generally relates to a system and method for producing an audible alert for a vehicle. More specifically, the present invention relates to a system and method for emanating from a vehicle an audible alert having a sound profile that is readily detectable by pedestrians.
2. Background Information
Electric and hybrid vehicles are becoming increasingly popular for reasons such as rising fuel costs and environmental concerns. A secondary advantage of the shift toward widespread use of electric vehicles is the reduction of ambient noise which is emanated by an internal combustion engine (ICE) used in most vehicles today. With 100% electric power running the vehicle, generally only tire noise and some slight electric motor noise is generated during operation of fully electric vehicles. Although this greatly reduces noise pollution, this lack of noise can make it difficult for pedestrians to detect the presence of a vehicle. That is, pedestrians are highly reliant on ICE noise to detect the presence of vehicles, especially when the pedestrian is hearing or visually impaired.
One attempted solution to enable better pedestrian detection of the vehicle is to emit a synthetic ICE sound during operation of the vehicle, thereby enabling detection of the electric vehicle in the same way as ICE vehicles. However, ICE sound generation does not reduce noise pollution. Other attempted solutions include the use of a physical apparatus, such as a cone or wheel that drops to engage the ground to create a sound. Still other solutions use a plurality of ultrasonic fields that cross to produce an audible sound in a selected area around the vehicle. Other attempts generate sounds can include, for example, generating an unpleasant horn-like sound at an ambient noise frequency, or generating a sound having peaks at an ambient noise frequency.